Lighting an active little guy

I'm shooting Tmax 400 in Rolleiflexes. I just got a Sunpak 555. I want to document my little guy (10 months old, crawling, on the verge of walking) in my home. He's in constant motion so focusing is a challenge. Ideally I'd like to be shooting at f/11 which is the appropriate aperature when the Sunpak is set to Auto. The problem is I don't like the dark background - the "Crime Scene Photo" look. When I pivot the flash head to bounce off the walls or ceiling my working aperature drops to f/4 - not good for DOF and tracking the little guy. Next I'm going to try using my SB-800 as an optical slave remote w/diffuser to light up the background.

I'm shooting Tmax 400 in Rolleiflexes. I just got a Sunpak 555. I want to document my little guy (10 months old, crawling, on the verge of walking) in my home. He's in constant motion so focusing is a challenge. Ideally I'd like to be shooting at f/11 which is the appropriate aperature when the Sunpak is set to Auto. The problem is I don't like the dark background - the "Crime Scene Photo" look. When I pivot the flash head to bounce off the walls or ceiling my working aperature drops to f/4 - not good for DOF and tracking the little guy. Next I'm going to try using my SB-800 as an optical slave remote w/diffuser to light up the background.

Any other tips, ideas?

Bouncing off a wall and ceiling is the right idea. If you take the Sunpack off of auto and crank up all the way it could get you to an 11, or close enough. Gots a flash meter?

Mount one flash on an umbrella in a fixed location and that's your main light. Use the other one aimed at the ceiling or wall to light the room. Have a long sync cord or wireless sync hooked up to the TLR. I use monolights, mostly so I can have modeling lights and I like cords more than batteries. Your flashes should work fine. I used to have an sb800, but sold it because it was far more features than I needed and I downgraded to an sb24. Lacking cords you could probably use the sb800 as a main light and aim your sunpack up to light the room.

Then you can move around as needed and the little guy can move around within the area lit by the umbrella. Could be a pretty big area as it's won't fall off too fast with the second flash lighting the room. If you have light energy to spare, you can use a non-reflective/sheer-white umbrella to both light the subject and the room.

Here's a shot with the main light in the photo; not ideally lit, but for reference. This is with my yashica C tlr at probably f11 or so. The room lighting flash is a little weaker than the main flash as it has to cover a bigger area.

Moved camera position about 120 degrees ccw around the table so the flash is to MY right by a couple feet. in the upper left you can see the wall is a little brighter because I have the room-lighting flash just out of the left of the photo.

Questionable answer:
Buy a second-hand Metz 60 CT1, that's a GN of 60 in metres, 100 ISO, or 120 in metres, 400 ISO. Set if fixed on a background wall; They are not expensive as they don't have any way to be "dedicated" to a camera (early models).
Use the Rolleiflex with its own flash to lit the baby as usual;
Find a way to synchronize your flash with the other one with photocells.

Stupid answer:
Buy a couple of big and powerful halogen lamps (the normal one, for your living room) or change the room bulbs with more powerful ones; Increase ambient light, that is. If you use B&W, anything will work.
Use 135;
Use 35mm;
Use f/5.6 or so. The background should be subdued but not sadly black. The DoF should be enough for "portrait" (supposing you want the take the entire figure, the environment, the toys, part of the house etc).

Blasphemous answer:
Use digital to practice. Revert to your Rolleiflex when you found the right setup.

Get a couple of flashes with cheap radio triggers and point them at the ceiling/corners of the room. Adjust their power until you get about f/11. You'll have pretty uniform and natural-looking light all across the room, so just chase the kid and push the button whenever. If shooting B&W, consider a green gel for the flash; it can improve skin tones in some cases. A red filter will make people look like white marble, if that's what you want.

If you light only the ceiling, the light can be a bit too directional and cause shadows under eyes/chins. I find it best to get about 3/4 of the light (depending on how bright your walls/floors are) on the ceiling and the rest on opposing walls, which will give you a nice ambient fill while still providing very good shading/rendering from subject shape.